It appears that 'cc.png' is a mask (test) layer. That 'bg.png' is a background, and that the rest are (separate) overlays displayed when over a 'cc.png' offset.

The overlays seem to have been generated from a gigantic file called 'tz_map.svgz' which takes about 1.5GB of RAM to open in Inkscape.

However, a pixmap seems to be missing for the Australia/Eucla timezone:
(gnome-control-center:2782): datetime-properties-WARNING **: Could not load hilight: Failed to open file '/usr/share/gnome-control-center/ui/datetime/timezone_8.75.png': No such file or directory

On 7 November 2013 18:44, Bastien Nocera <email address hidden> wrote:
> We ran into more problems with the timezone map. Are the source files
> available somewhere now?
>

Yes, in lp:timezonemap. In src/data there is the original svg. I think
in the svg one needs to modify layers and union/subtract them and then
generate new set of timezone bands.
My SVG / vector skills are not up to scratch to perform those tasks.

Hadess: I had been looking that this; and my presumption is that each layer shown/hidden/exported from Inkscape one at a time. But it's definitely something that I'll make scripted so it's easy to re-export the whole suite at $preferred_bitmap_size.